FIG. 1 illustrates a block diagram of a radiotelephone system 100 in accordance with the prior art. The radiotelephone system 100 generally comprises a controller 104, at least a first base station 106 and a second base station 108 and at least a first mobile station 10 and a second mobile station 112. The controller 104 is coupled to a public switched telephone network (PSTN) 102 which forms a landline telephone system. The base stations 106 and 108 communicate with the mobile stations 110 and 112 over radio frequency (RF) channels. The first base station 106 has a geographic coverage area 114 and the second base station 108 has a geographic coverage area 116. The mobile stations 110 and 112 can communicate with the base stations 106 and 108 when the mobile stations 110 and 112 are within the respective geographic coverage areas 1 14 and 116. The controller 104 routes calls for the mobile stations 110 and 112 between the PSTN 102 and the base stations 106 and 108 or between the base stations 106 and 108 themselves. When the geographic coverage areas 114 and 116 overlap, the controller also coordinates handoffs of the mobile stations 110 and 112 between the geographic coverage areas 114 and 116 of the base stations 106 and 108, respectively, when the mobile stations 110 and 112 are in calls. Examples of the radiotelephone system 100 include cellular radiotelephone systems and wireless private branch exchange (PBX) systems. In these types of radiotelephone systems, the base stations 106 and 108 typically have large geographical coverage areas which service many mobile stations. Because of scale and demands on these types of radiotelephone systems, they are complicated and costly to install and maintain. The cost is typically paid for by users of the mobile stations 10 and 112, such as in a cellular radiotelephone system.
FIG. 2 illustrates a block diagram of a cordless radiotelephone system 200 in accordance with the prior art. The cordless radiotelephone system 200 comprises a base station 202, including a simple, integral controller 206, and at least one portable handset 204. The base station 202 is coupled to a public switched telephone network (PSTN) 208 which forms a landline telephone system. The base station 202 communicates with the portable handset 204 over radio frequency (RF) channels. The base station 202 has a geographic coverage area 210. The portable handset 204 can communicate with the base station 202 when the portable handset 204 is within the geographic coverage area. The controller 206 directs calls between the PSTN 208 and the base station 202 for the portable handset 204. Examples of the radiotelephone system 200 include cordless phones operating at 46 to 49 MHz or at 902 to 928 MHz. In these types of radiotelephone systems, the base station 202 typically has a small geographical coverage area, such as a few hundred feet, which service one or a few portable handsets. These types of radiotelephone systems are relatively simple and inexpensive when compared to the radiotelephone system 100 of FIG. 1. A user typically bears the entire cost of the radiotelephone system 200 and it is usable with the wired connection to the PSTN for which the user already pays a subscription fee. The limited geographic coverage area of the base station 202 is widely accepted and appreciated by users because this type of radiotelephone system has a relatively low cost and provides the users greater mobility than a conventional corded telephone.
A problem with radiotelephone systems 100 and 200 is that there are few communication systems that offer communication capabilities in between the radiotelephone systems 100 and 200. For example, although the cordless radiotelephone system 200 provides low initial system cost, is usable with the wired connection to the PSTN for which the user is already paying a fee, and cordless convenience, the user may need a more range than a few hundred feet typically provided by the cordless radiotelephone system 200 of FIG. 2. The extended geographic coverage area may be desired to reach a location, relatively near to but outside the geographic coverage area 210 of the cordless telephone system 200 of FIG. 2, such as a garage, a barn or a distant location in a large building, for example. Although the radiotelephone system 100 of FIG. 1 provides greater mobility, the user is required to pay an ongoing subscription fee. Presently, the subscription fee for the radiotelephone system 100 of FIG. 1 is too expensive in order to justify reaching a location, relatively near to but outside the geographic coverage area 210 of the cordless telephone system 200 of FIG. 2.
Accordingly, there is a need for a cordless radiotelephone system having an extended geographic coverage area without incurring the additional complexity and cost associated with the radiotelephone system 100.